北京奥林匹克森林公园不同植被类型土壤呼吸时空动态特征OA

[Objective]This study aims to investigate the spatiotemporal dynamics,as well as the driving factors of soil respiration across different vegetation types of urban forests,so as to provide theoretical references for regional carbon estimation.[Method]Taking Beijing Olympic Forest Park as the research object,a portable soil respiration measurement system was used to measure soil respiration(Rs),soil temperature(Ts),and soil water content(CSW)of 26 sample plots(13 in the arbor community and 13 in the arbor-shrub mixed community)monthly from April to October in 2023.And combined with high-resolution n ormalized difference vegetation index(INDV),a fitting analysis was conducted on the seasonal and spatial variations of Rs and the influencing factors.[Result](1)The seasonal dynamics of Rs and Ts were consistent,showing a unimodal pattern of first increasing and then decreasing.The average Rs in the arbor community(4.83 μmol·m-2·s-1)was higher than that in the arbor-shrub mixed community(4.42 μmol·m-2·s-1).(2)Ts accounted for 90.0%and 73.0%of the seasonal variation in Rs in the arbor and arbor-shrub mixed community,respectively,while CSW explained 28.0%and 37.0%.A dual-factor model incorporating both temperature and moisture could explain 93.0%and 82.0%of the variation,respectively.(3)The spatial coefficient of variation of Rs in the arbor-shrub mixed community was similar to the variation trend of CSW,with a significant positive correlation between the two(R2=0.88,P＜0.01).In contrast,there was a highly significant nonlinear relationship between the spatial variation of Rs and Ts(R2=0.65,P＜0.01)in the arbor community.(4)The response of Rs to Ts varied in time and space,with an approximately linear increase in time and a nonlinear response in space.Although Rs increased with the increase of CSW in both time and space,the rate of increase varied.[Conclusion]The response of Rs to environmental factors in urban forests exhibits spatiotemporal variations.Ts is the driving factor of seasonal variations in Rs,while the dominant factors of spatial variation of urban forest Rs vary among different vegetation types.[Ch,6 fig.2 tab.38 ref.]